The part of the feet (incl. any part of the tarsus) which extends beyond the tail tip in flight[1].
References[]
^Mullarney, Killian; Lars Svensson, Dan Zetterström and Peter J. Grant (1999). Birds of Europe. Princeton University Press. ISBN0691050538.Cite uses deprecated parameter |coauthor= (help)
This article is part of Project Glossary, an All Birds project that aims to write comprehensive articles on each term related to animals.